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Discussion Starter · #1 ·
Me and my friend were having a dicussion over the amount of power coming out of the 4BT, I thought that it was 400 coming out of a stock 4BT with the factory rev limiter at 2500, but the document on the yahoo groups page (4BT39.pdf) claims that it's only 231, is that correct?


Pantherman
 

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The torque rating on the 89 - 93 6BT was 400. Different 4BT CPL numbers have different hp/tq ratings so the chart is correct for that particular CPL build.
 

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Discussion Starter · #3 ·
The torque rating on the 89 - 93 6BT was 400. Different 4BT CPL numbers have different hp/tq ratings so the chart is correct for that particular CPL build.
Ok, thanks. I had forgotten about the CPL numbers :rolleyes:

Pantherman
 

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As I recall a 4BT CPL 858 is rated at 105hp and 305 ft lbs torque. Cummins is famous for ummmmm, conservative estimates....;)
 

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Me and my friend were having a dicussion over the amount of power coming out of the 4BT, I thought that it was 400 coming out of a stock 4BT with the factory rev limiter at 2500, but the document on the yahoo groups page (4BT39.pdf) claims that it's only 231, is that correct?


Pantherman
231 sounds like where it would be right off of the idle speed (750-900 rpms)
 

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torque

Doe you want peak torque or torque at rated speed?
 

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pretty sure it is 4BT 105hp 265 ft/lbs and 4BTA 120hp 305ft/lbs...
 

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Does anyone have a chart, or list, showing various CPL numbers and their rated outputs? I have estimated mine, but I'm sure its far from accurate. I just used other ratings, and estimated mine from those.

Jim
 

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rating/curves

let me know what you are looking for and I can email them to you..................4 cylinders or 6 cylinders..
natural, turbo'd or aftercooled.Steve
 

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Discussion Starter · #10 ·
Doe you want peak torque or torque at rated speed?
Sorry, I was away from the computer for a few days. The thing is that we were talking about tranny's to use, he wants to use a NV3500 (rated for 300Ft/lbs of torque) and I just don't want to put $$ into what will be a casing full of metal shavings after I'm done using it.

It's an '89 CPL # 858

Pantherman
 

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I ran my standard duty NV4500 with 305 ft lbs stock, before I turned it up, with no issues what so ever. I also put the trans through hell with towing and lots of wheeling. The HD NV4500 which are slightly beefier and have a vibration dampener, are one of the few trans that nutoriously holds up to even beefed up Dodge 6BTs with 800-1000 ft lbs. I would not hesitate to run a good condition NV4500 in the slightest.. A NV3500 perhaps, but even a standard duty 23 spline NV4500 should be fine for most 4BT applications...
 

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Sorry, I was away from the computer for a few days. The thing is that we were talking about tranny's to use, he wants to use a NV3500 (rated for 300Ft/lbs of torque) and I just don't want to put $$ into what will be a casing full of metal shavings after I'm done using it.

It's an '89 CPL # 858

Pantherman
Your engine is 105hp 2500 , 265 ftlb @1700.

Scott
 

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You have 300 ftlb @1500 RPM (peak) 18 * timing
Your engine is 105hp 2500 265 ftlb @1700.
I wonder what the primary differences are - - just the aftercooler, 1/2 point of compression, and nothing else?
 

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So I have a P7100? I was under the impression it was an 'A' series pump, Is there any way to visually confirm this? When I ran the number past cummins in town they said it was the 'A' series.

-andrew
 

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I might have misunderstood your question, but: Cummins 4B is normally aspirated, no 'T' Turbo; 4BT is Turbo'd no aftercooler; 4BTA is Turbo'd and Aftercooled. 4BTA is most desireable, as more power but without high EGT's Exhaust Gas Temperatures. Either a 4BT or 4BTA is usually fine for a swap, just a higher power potential with the aftercooler.
 

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4BTA is most desireable, as more power but without high EGT's Exhaust Gas Temperatures. Either a 4BT or 4BTA is usually fine for a swap, just a higher power potential with the aftercooler.
I wouldn't go out of my way to find (or pay a premium for) a 4BTA.
You can get a pretty good size, brand new air-to-air intercooler for $100 and add it to a 4BT.
 
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